pop

Pops and returns the last value of the array, shortening the array by
one element.

Returns the undefined value if the array is empty, although this may
also happen at other times. If ARRAY is omitted, pops the
@ARGV array in the main program, but the
@_ array in subroutines, just like
shift.

Starting with Perl 5.14, an experimental feature allowed
pop to take a
scalar expression. This experiment has been deemed unsuccessful, and was
removed as of Perl 5.24.

perldoc.perl.org - Official documentation for the Perl programming language